Air and fuel supply means for liquid fuel burners of the bowl type



Oct. 2l, 1952 L. s. cHADwlcK ET AL 2,614,618

AIR AND FUEL SUPPLY MEANS FOR LIQUID FUEL BURNERS oF THE Bowl. TYPE 3Sheets-Sheet 1 Filed sept. 21, 1948 l.. s. cHADwlcK ET AL 2,614,618 AIRAND FUEL SUPPLY MEANS FOR LIQUID FUEL BURNERS oF THE Bowl. TYPE Oct. Z1,1952 s Sheets-sheet 2 Filed Sept. 2l, 1948 3 Sheets-Sheet 3 MEANS FORLIQUID FUEL.

OWL. TYPE:

INVENTORl EVANS w. cnaesamnw i o r' n ggf L. S. CHADWICK ET AL BURNERSOF THE B AIR AND FUEL SUPPLY Oct. 21, 1952 Filed sept. 21. 1948 LEE 5.CHHDW1CK BY RRTHUR R- MOORE `lytically cracked fuels,

yburners that is Patented Oct. 21, 1952 s -VUNITED STATES YPATENT *lOFFICE' AIRAND FUEL SUPPLY MEANS Fon LIQUID ,i

FUEL BURNERS THE BOWL TYPE I .j Lee S. Chadwick, vShaker Heights, Evanst Cheeseman, Lakewood, and Arthur R. Moore,

Cleveland, vOh'iofassgnors to Perfection Stove Company, Cleveland, Ohio,a corporation of Application september' 21`,194s,se`ria1No. 50,312

12 claims. (o1. 15s- 91) the'bowl'or pot type, and more particularly toimproved means for admitting fuel and air-there- Heretofore, withrespect to burners ofthe above mentioned type, carbon deposit, and theaccumulation of other` fuel residues, in andabout" the fuel inlet ofthelbowl, have attended the operation of thevburners; and this,obviously, hask necessitated frequent cleaning, and occasional repairand replacement of the fuel inletl means.

This unfavorable condition, which is especially pronounced in theburning of the so'fcalled catadevelops at arrate into the size of thefire. AIn during Ylow versely proportionate other-words, it grows morerapidly or pilotf fire operation. ,s

We have discovered that, in order to successfully burn thebeforementioned catalytically cracked orsimilar fuel in a bowl typeburner, it is necessarylthat the fuel be maintained at arrelativelylowtemperature during its passage from the fuel supply and meteringmeansjcornmon in the type of burner above referred to,to the point ofits liberation withinvther bowl. However,L after its being liberated,the fuel vmust be rapidly transformed into a state suitable forcombustion, which generallyV means that it must be converted from liquidto gas andimmediately mixed with a predeterminedamount of air. It isessential, on the other hand, lthat actual combustion take placerelatively remote from the point where'the fuel is liberated so that thefuel discharge means or tip` of the fuel supply pipe will be maintainedat acomparatively low temperature in order to prevent undesirablecracking of the fuel and the ensuing" deposit of carbon and residue inor upon said means or tip.

- and which is characterized by'additional'means It is, therefore, thelprimary object of our invention to provide, in a bowl type burner,means for supplying liquid fuel and air to the bowl in properproportions and in a manner to bring about theA results above set forth,and which is equally effective at all stages of burner operation,frornlowor pilot both inclusive. l y It is'- anotherobject of theinvention to provide means ofthe above-described character that insureseflicient burning of the fuel at all stages of burner operation.

Another object of the invention 4is to provide fuel and combustion airinlet means for bowl type so related to the region of lcoinbustion thatthe combustion air is preheatedy a limited amount before beingdischarged into the bowl. l Y

fire to high or maximum re,

l single wall tube with the 'radiation of heat, durf y ing .higher reconditions, Afrom the flame to the r:fuelspread over the bottom of theburner bowl.

posed peripherally of It is anotherobject of the invention to provide aliquid fuel burnerv of the type aforesaid including lan air housingabout the burner bowl and wherein there are air admitting means'disthebowl through which its interior communicates with that of the housing,

for conveying air to thefcentral'region of the bowl, said additionalmeans beingso constructed and arranged as to effect a proper control andYdistribution of the air, thereby to assure stable conditions -ofcombustion 'at all stages 'of re.

vA further object ofthe invention is-to provide a bowl typeburnerincorporating means for delivering fuel and a proportionalamount-of combustion air to an area within the bowl a suitable `distanceabove the bottom thereof and vin such manner that the fuel, as it isliberated'and drops to the bottom of the bowl, will be envelpedin thecombustion ^air,-whereby, upon `vaporiaation andignition of the fuel,combustion will be'localvized Ato a given region of the'bottom of theAbowl in spaced relation to the pointof admission of 'the fuel.'

With the fuel-and air thus delivered to the burner bowl and :combustionlocalized as described, it is protected from abnormalconditions ordisturbances, such as air currents or eddies caused within ythe bowl bydown drafts in the chimney'to which the burner is connected,

or such aswould be caused by momentary interruptions inthe supply offuel to the burner.

A still further and fundamental object of the 'invention is to provide aconstruction wherein` the fuel 'supply pipe is so vrelated lto the com.bustion airsupply means that said pipe is maintained at `a relativelylowtemperature during burner operation,thereby toavoid the conditionsconducive to carbon formation.

l The invention is susceptible to differentv embodiments, two beingdisclosed herein, characterized, respectively, by a single wall airvsupply tube, and by a double vwall air supply tube. 'The latter has theadvantage of providing an insulating space between the inner and outer*`walls of the air supply tube which, obviously, maintains the incomingcombustion-air at a lower temperature than would otherwise be the case;and as a consequence of this theoutside diameter of the double wall airsupply tube may be less than'that of the single wall modification, underwhich circumstances-itwould interfere less than the larger Anotherobject of the invention is to provide a dischargetip-l of`.novelcharacter for the fuelsupply pipe that will liberate the fuel insmaller droplets and with greater frequency than occurs when theconventional shaped tip is employed, and which..lat ter.isforrnedbycutting or trimming thel dischargefend of the fuel supply pipe in aplane normal tothe axis of the tube in the immediate region of said end.Our improved tip l is especially advantageous when the fuel is fed at anextremely low rate, suc-h'as` for pilot -or low re. In this connectionit may beeXplaine'd that when the fuel is fed in larger drops atrelatively longY intervals, a fluctuating re lresults-that ,is

'. bottom w 1.21;

wall 20go ,th2;hQusing H ts over a cylindrical hard to control becauseoffthediinculty ofsup--i l plying the requisite amount 'of combustionain v under such circumstances.

Other objects will appearas we rproceed to describe the herein disclosedembodiments of the' invention and among which are convenience` of fassembly and disassembly, ready accessibility of the parts, and ease offabrication,v

' In theaccompanying*drawings that form a part hereof and wherein likereference characters des- Aignate;like parts inthe different views, Fig,A1

,but lessxcomprehensive. than Fig. 1, showing an- .other. formfoftheinvention; Figs. 5 and 6 are .sectionalfdetails on the.respectivelines 5 5 and @+6 of Fig, 4; Fig.- 5 :being on av somewhat enlargedscale, and Fig. lisa View, similar to Fig. 4,

v.showing the inner' air tube and the` fuel supply pipe partiallywithdrawn` from the assembly.-

Wegshall first describe the simpler -form of our invention; AillustratedinFigs; 1, 2 and Sywherein asinglewall air supply tube Iv is shown aspassing diametrically through the burner bowl, the latter beingYdesignated generally by the reference letteryB. The burner -bowl isshown kas fabricatedffrom sheet .metalparts includingy a cylindricalperipheral wall 2, to the respective upper and lower ends'of which aresuitably connected, as by welding, an annular top wall 3 and a circularbottom wall il.` Shown asl connected by a seam 5 to the top wall 3 abouttherlarge central opening thereof is an .upwardly divergent perforatedthroatmem- `ber 6 which has its outer'edge portion overlying -andconnected to an annular, stepped member 1. This member is -detachablyconnected by fastening means 8 to the lbottomwall 9 of a'structure shown'in `broken lines and which` includesvertical wall portions Ill. Saidstructure encloses a combustion chamber or space C that communicateswith the interior of the burner bowl through a large openingin thebottom wall 9 andthe passage wherewith it registers` that is surroundedand thus defined by thel steppedy member?, throat member 6,

andl top wall 3. Said top wall 3 and member'l are frigidly connectedtogether at circumferen-l tially spaced points by ties I5 in accordancewith prior practice. i

vThe central portion of the bottom wall 4 is depressed to provide anoilsurnp of considerable areaand, at its center,- said wall is shown as`formed to provide a shallow cup I6 that is preferably occupied by abody or vdisc of pervious re fractory material. A material foundespecially suitableV for our Ipurpose is a relatively coarse Fordescriptive purposes l grained sinteredmetal. y the,y aforesaid body orvdisc of Apcrvous material,

. 4 or, in its absence, the interior of the cup I6, will be referred toas the target I8.

Enclosing the burner bowl B is a housing that is designated generallybythe reference letter H andthatfconsist's of afcylindricaligperipheralwall 2U andl a slightly'dished'circularbottom wall 2I. 'I he bottom wallhas a relatively large central opening surrounded by a depending flange22, a'nd-tted `overthelatter is the outwardly flanged upperend of arelatively shallow sheet metal cup 23, s aid cup. being fastened, as bywelding, to the vThe upper end of the peripheral v.portion oflfthevpreviously mentioned annular stepped member 'Lithe overlying portionsof said wall and. member. being welded or otherwise secured together.The peripheral wall of the housing H is radially spaced from theperipheral wall 2 of the burner bowl B to provide an air space thatsurrounds the burner Ybowl and communicateswithits interior throughperforations 2a in the wall 2. vThe air space S also communicates withthe combustion chamber or space C through the perforations 6a of thethroat member Bjand through an aperture in thel member l, over whichaperture is an air director or hoody 26. This latter fea-tureconstitutesno part of my invention, but is disclosed and claimed in the`applicationof Marc Resek, et al., Serial No. 789,052, filed December 11947.

.with the aii` supply'tube I, and projecting inwardly through said holeis atubular extension I@ through which the outlet of the scroll casingof a centrifugal fan or blower F` hascommunicative connection with theair supply tube I.v For present purposes, said extension and tube may beregarded as a unit, and the samemaybe described as extendinginwardlythrough the openingin the wall 20 and diametrically through theburner bowl I and as having its end. portions sealed in holesinl opposedparts of the wall 2. -The end of the air supply tube remote from thevfan or blower F opens into theair'space S. Said fan orblower isoperated by an electricmotor M that is shown as attached to the side ofthe beforementioned scroll casing.

Opposite the inner or discharge end of the air supply tube I, the wall20 of thehousing H is provided with an opening that is normally closedby a plate 36. The plate is` shown as attached to said wall by screws3l, and as having a central aperture 38through which a fuel supply pipeisiextended inwardly, thev pipe continuing within the air supply tube Ito about the longil ported by a member I that may a convenient part ofthe apparatus.

substantially semi-cylindrical socket portion 46 wherein the -piperests, said socket portion desirably embracing something more than halfthe pipe so that the pipe will snap into the socket when fullydepressed. At its outer end, thek fuel supply pipe has connection,through a' coupling 48with a tubular outlet 49 of' a liquid fuely supplyand control'means 50. This means desirably consists of a so-calledconstant level valve, an article well known to those familiar with thesubject to which the invention relates. The liquid fuel supply andcontrol meansA 50 is shownvas supbe attached to In order to avoidflooding of the burnerzbowl, and to provide for a definite maximumlliquid level therein, the depressed portion of the bottom wall 4 of thebowl is provided with an overflow opening 5.5, from which a pipe 56leads to Aa vessel 51. This vessel encloses a float 5B that hasoperative connection, through a rod 59, with trip mechanism of theliquid fuel supply and control means 50., Such trip mechanism is a partof the previously mentioned well known constant level valve that isemployedv in the present instance as the liquid fuel supply and controlmeans. When liquid fuel rises within the burner bowl to an abnormalheight, and the excess escapes through the overflow opening 55, saidexcess fuel drains tothe vessel 51 through the pipe 56 and lifts thefloat w5,3 thereby to operate the aforesaid trip y mechanismand stoptheiiowk of oil through the pipe 46. Communicating with the lowest partof the pipe 56 is a drain valve 60 through which the vessel 51 and pipe56 may be emptied of liquid fuel at the time of resetting the tripmechanism. This restores the apparatus to condition for normaloperation.

When the apparatus is in operation, oil will be delivered to the burnerbowl through vthe pipe 40 at a rate depending uponthe adjustment of theliquid fuel supply and control means 5G. By'this means the fuel may befed at different rates to produce low or pilot lire, intermediate fire,and high or maximum re. In any event, the fuel drops from the dischargeend or tip of the tube 40 onto the target I8. It will be understood, ofcourse, that during operation of the apparatus, the motor M is energizedand drives the fan orvblower F which impels air through the 4tube I intothe space S and, through the aperture 42 of said tube, into the lowerportion of the burner bowl. The air entering the bowl through theaperture 42 is more or less in the form of a columnr that is projectedtoward the target I8 about the fuel that drops from the pipe 4D. Theburner may be lighted by any suitable means, as by a burning taper orthe like introduced through the lighting and cleanout opening 36. Veryshortly after` the burner is lighted, the target I8 and the surroundingportion of the bottom wall of the burnerbowl become sufficiently heatedto vaporize the oil. The vapors immediately commingle with the air insufficient amount to render combustion subthat is projected downwardlythrough the aperture 42 andthe mixture burns within the bowl.`

stantially complete, enters through the perfoi'ations 2i in theperipheral wall of the bowl. Under these conditions the products escapethrough the open top of the bowl into the combustion space or chamber C.When the fuel supply is increased by an appropriate adjustment of themeans v50 (whether it be accomplished-manually or by thermostatic means,in which latter event the/apparatus would be equipped with an automaticcontrol system .of usual character) the .droppingof the oil quickens andthe volume of the irein-Y creases. Under these circumstances theairentering through the aperture 42 supplies only a part of the primaryair, the balance vvbeing supplied through the perforations 2a of thewall 2. During high or maximum fire, substantially the entire capacityof the perforations 2a is needed to supply the requisite amount ofprimary air, wherefore a rich mixture fills the bowl and, as it risesthrough the throat member 6, it receives secondary air through theperforations 6a and is thus conditioned for combustion within thecombustion space or chamber C.

During all stages of operation, the discharge end or tip and adjacentportion of the fuel supply pipe 4D is maintained "relatively cool by thesurrounding column of air, while the air supply tube itself is kept at arelatively low temperature by the air stream that is constantly flowingthrough it. Also, the region of said tube above the target I8 isprotected from the intense heat of vcombustion by the presence of theair issuing through the aperture 42. As a consequence of the favorabletemperature conditions just described, carbon deposit and theaccumulation of other fuel residues within or upon the tip ofthe fuelpipe is prevented, and deterioration of the air supply tube is avoided.While we have referred to relatively low` temperatures of the air supplytube andfuel supply pipe, it will be understood that operatingtemperatures within the bowl will be high enough to cause the airflowing through the air supply tube to be preheated to a desirabledegree.

What we at present consider the preferred form of our invention isillustrated in Figs. 4 to 7, where the air supply tube is of double wallconstruction, and the oil supply pipe is formed with a unique tip. Thismodification we shall now describe.

The air supply tube, designated generally by the numeral IUD', consistsof an inner cylindrical wall IIlI and an outer cylindrical wallr |02that are maintained in radially spaced, and desirably'concentric,relation to each other by collars |03 and |04 that are substantiallyZ-shaped in cross section. The llarger ends of these collars fit withinthe ends of the outer cylindrical wall E02, while their smaller ends iitabout the adjacent-portions n of the inner wall. lill. The larger end'ofcollar ID3 is welded or otherwise secured to the adjacent end of saidouter wall I 62, While the smaller end of collar E64 is similarlyfastened to the inner wall IIlI. The reverse ends of said collars areunxed with respect yto the walls wherewith they cooperate. The ends ofthe outer wall |02 are projected through holes of appropriate size indiametrically opposed portions of the peripheral wall 2 of the burnerbowl, and are welded or otherwise fastened to said wall. The portionofthe peripheral wall 2i) of the housing H that is nearest thecollarzI03 is provided with an opening shown as surrounded by a flange Illl that is axially -alignedwith vsaidcollar and is substantially equalin inside diameter to .the outside diameter of the Walll Alsolv the:portion: of said housing wall 2|! that is adjacent the .collar i'iliisprovided with anfopenng H l aligned with saidcoll'ar and thatis'somewhatgreater in `dituneter thanthe larger endl thereof. Thislattero'pening'lis.adapted to be close'diby a plate ||2:.'tha`t is shownas fastened tothe Wall 2B. by .screws When .the parts. of thefassembly.arein normal-relation, as shownL in Fig.: 4;'the.inner: wall IDIprojects a'substantial distance-through .the collar. 103,1" across theair space:S and intoitlieange H8; Shown engaged over theaan-ge. Hliis`the outlet connection ofthe scroll casing oft-liefern or blower F.Supported within and permanentlyzconnected. tothe cylindrical wall ||l|,through hangers H5, is. a' fuel supply pipe |2|3` `that enters thehousing through afh'ole |2| in the previously Vmentioned plate. i i2.Itrwillbe understood that the outer end of the fueli supply pipe l isadapted z to be connected, throughia coupling |22,` with a fuel supplyand control means, such as that 'shown at 5U .in Fig. 1.' The'inner endofthe fuel .supplypipe |20v is curved downwardly and terminates in aunique oilfeeding tip ithat is formed by cutting away th'eisides'ofthe.tube atan angle, as best shown inzlig. 5,. tov formA two pointed,laterally curved beaksxthatiaresthen iiattened and: pressed toward eachother to dispose ther'nfin slightly'spaced parallelrelaitionf.` The vtipiiprojects through an aperture|28in the inner wall |534 that registerswithalarger aperture |29in' the outer wall |92. A lug-430i extendsradiallyrfrom'the larger'end of the-collary lil'lliand, when kthe partsare in normal relation, said lug occupies a notch' |3| .in the adjacentend of thewall |82. Thus, vided-v f'or positioningV the' inner wall liliinr such relation to the: fixedV outer wall H32V that the aforesaidapertures.. |28'and'l29- are in register, and theftip is directly abovethe target I8.

In general, the operation ofV the Vpresent 'form of` thefinvention isthe same as that-of 'the `form previously described. However, in thepresent case, at a-correspondingrate of flow, the fuel is delivered insmaller drops and with greater frequency than'in the former case. Thisresult is due tothe difference in the discharge end or tip of the fuelsupply pipe, and it contributes to a more even nre, a more uniformvaporization of the fuel, anda better mixture of primary air with thevapors. Also, experience has shown that there is less tendency forcarbon and other fuel residues to form or accumulate in or upon a tip ofthe style shown in Figs. 4 and 5.

Furthermore, because of the double wall construction of the air supplytube |00, with its insulating air space, thetemperature of thecombustion air is better' controlled; and a further advantage is thatthis construction admits of a smaller external diameter than the singlewall tube; thereby afording a larger vaporizing area during higher nre,as already pointed out.

It is also evident from the construction at present under considerationthat the inner and outer walls of the air` supply tube are capable ofindependent elongation and contraction. Therefore, the outer wall |92,which has its ends fase tened tothe peripheral wall 2 of the burnerbowl, is Vfree to expand and contract with the latter wall undertemperature-changesand independently of the inner wall IIJ which is keptrelatively cool by the air flowing through it. Accordingly,undesirablestresses are not so likely to occur in the double wall airtubev construction as in the single tubeembodiment where such stressesin the structure vmight resultrfrom" the'difference in tem- 8i peraturebetween the tube and theburner'bowl wallZ rto which saidy tube isrigidly connected.

InV Fig. 7 'we have shown ho-w the inner cylin, drical wallV {l-l may beWithdrawn from the assemf bly orl replaced, when the plate ||2 isremoved from the opening of the wall 2D.

Having thus described our invention, what we claim is:

1. Inliquid/fuel burning apparatus, the combination of a burner bowlincluding aperipheral Wallya housing enclosing, saidvbowl and having aperipheral wall spaced from the` corresponding wall of the bowl, an'airsupply tube extendinginwardly through the peripheral Wall of the housingand entirely through the bowl and openingY at its inner end into thespace between said walls,'the tube having an aperture in its lower sidethrough which the interior of the tube communicates with that of thebowl, and a fuelr supply pipe projecting into the air supply tube and.arranged with its discharge end above said aperture.

2. In liquid fuel burning apparatus, the combination of a burner bowlincluding a peripheral Wall, a housing enclosing said bowl and having aperipheral wall spaced from the corresponding wall of the bowl, an airsupply tube extending inwardly through the peripheral wall of thehousing and diametrically through the bowl and opening at'its inner endinto the space between said walls, vthe tube having an aperture in itslower side through which it communicates with the bowl, and a fuelsupply pipe projectingV in# wardly through the peripheral wall of thehous- Ying substantially diametrically opposite the entrance of the airsupply tube through said wall and continuing into the air supply tubeand having its inner end turned downwardly and arranged substantiallywithin the area of said aperture.

3. In liquid fuel burning apparatus, the combination of a burner bowlincluding a peripheral wall and a bottom wall, a housing enclosing saidbowl and having walls spaced from the peripheral and bottom wallsof thebowl, an air supply tube extending inwardly through the peripheral wallofthe housing and diametrically and horizontally through the bowl andopening at its inner end into the space between the peripheral walls ofthe bowl and housing, said tube being spaced a substantial distanceabove the bottom wall of the bowl and having an aperture in its'lowerside substantially coincident with the vertical axis o f the bowl, and afuel supply pipe projecting through the peripheral wall of the housingand into the air supply tube through the inner end thereof and havingits discharge end turned downwardly'in alignment with said aperture, thebottom wall'of the bowl having a central depresi sion.

4. The combination of elements dened by 'claim l3, plus: a targetconsisting of a body of pervious refractory material occupying saiddepression.

5.v In liquid fuel burning apparatus, the combination of arburner bowlincluding a peripheral wall and a bottom wall, a housing enclosing saidbowl and having a peripheral wall spaced from the corresponding wall ofthe bowl, substantially dia-metrically opposite portions of theperipheral Walls of the bowl and housing having substantially axiallyaligned openings, an air supply tube extending inwardly through one ofthe'openings of the housing wall and through the burner bowl and khavingits inner end Xed within the Opening-of.v the burner bowl wall' at theside thereof line bottom wan "of l .6. lInliquid fuel remotefroinithatgthrough whichithe air supply tube enters the housing, the airsupply tube Ahaving Vanaperture in its loweriside at 'about the,-vfrtcal center of y rrivabiyjattached to theV peripheral waiior theicusingpver the opening l inner'end of .the air ing a hole, an oilsupply pipe extendingV inwardly Y '.throughfsaid holeand into the airsupply ,tube

the'rein adjacent the supply tube, `said plate hav- `"and havingy itsinner end turned` downwardly and alignedv/lithl the aperture 'of they'air supply' tube,

the bowl'having a depression' inv vertical alignment with said aperture,and a target consistingof abodyl of -pervious refractory materialoccupying said depression.

burning apparatus, the comybinationof elements defined ,by claim 5,plus: a

tube surrounding and radially spaced `from the air supply tube withinthe burner bowl and hav- Y ling an aperture registering with that ofsaid air'` supply tube.

7. In liquid fuel burning apparatus, the combination of a burner bowl,an air supply tube extending substantially horizontally into the bowland having an aperture through which it communicates with the interiorof the bowl, said aperture being located on the underside of the tube,and a fuel supply'pipe projecting into the air supply tube and arrangedwith its discharge tip substantially within the area of said aperture,said tip being characterized by opposed with the interiorof the bowl,said aperture being located on the under side of the tube, a fuel supplypipe projecting into the air supply tube and arranged with its dischargeend substantially within the area of said aperture, said air supply tubebeing spaced a substantial distance above the bottom of the bowl, and aheat insulator in shielding relation to the air supply tube.

9. In liquid vfuel burning apparatus, the combination of a burner bowlincluding a peripheral wall having substantially diametrically opposedopenings spaced a substantial distance above the bottom of the bowl, atube extending through the bowl and'having its ends fixed in saidopenings, a housing enclosing the burner' bowl and having a peripheralwall spaced from the corresponding wall of the bowl and provided withopenings aligned with those in the peripheral wall of the bowl, an airsupply tube of smaller diameter than the formertube extending inwardlythrough one of said openings in the peripheral wall of the housing andaxially through the aforesaid tube and terminating adjacent the end ofthe first mentioned tube remote from that through which the air tubeenters said first mentioned tube, means supporting and spacing the airsupply tube from the first mentioned tube, the air supply tube and therst mentioned tube lhaving registering apertures on their lower sidesthat are substantially central of the burner bowl, and a liquid fuelsupply tube entering through the other opening of the peripheral wall ofthe housing and ,projecting into theair, supply tube and Y having itsinnen, discharge .s end; ,turnedy ldownyply tube and fitting withinwardly kin alignment with the-j aforesaid apertures. l

1G. In

tial distance above-,thebottomwall ofthe bowl,

a tube disposedv across the burner bowl and hav- A ringiits endsfixedwithin said openings, ahousing enclosing the .burner bowland-having aL peripheral wall spaced from the correspondingH wall of thebowl, said .peripheral havingfopeningsjthat are substantially in axialalignment with'theaforesaid tube, an air supply tube extending axiallythrough the aforesaid tube and having one of =its `ends within one ofthe openings of the vperipheral wall of the Vhousing and its other endsubstantially intheplane-,of the corresponding end of` their lowersides, collars embracing the air supthe ends of the first mentionedtube, and a fuel supply pipe extending through the other opening in theperipheral wall of the housing and into the air supply tube and havingits inner end turned downwardly and aligned with the apertures of saidtubes.

1l. In liquid fuel burning apparatus, the combination of a burner bowlincluding a peripheral wall and a bottom wall,V substantiallydiametrically opposed portions of said peripheral wall having openingsthat are spaced a substantial distance above the'bottom wall of thebowl, a tube disposed across the burner bowl and having its ends fixedwithin 'said openings, a housing enclosing the burner bowl and having aperipheral wall spaced from the corresponding wall of the bowl, saidperipheral wall ofthe housing having openings that are substantially inaxialalignment with the aforesaid tube, one of said openings being of adiameter at least as great as that of the aforesaid tube and the otheropening being of somewhat lesser diameter, an outwardlyextending flangesurrounding the smaller opening, an air 'supply tube extending axially*Vthrough the aforesaid tube and having oneA of its ends supported withinthe beforementioned flange and its other end adjacent the correspondingend of the rst mentioned tube,

said tubes having registering apertures in their lower sides that aresubstantially central of the burner bowl, collars embracing the airsupply tube and fitting within the ends of the rst mentioned tube, thecollar nearest the end of the air supply tube that occupies said flangebeing fastened to thev rst mentioned tube, andthe other collar beingfastened to the air supply tube, whereby the air supply tube, with thelast mentioned collar attached, may be slid free of the other collar andwithdrawn from the first mentioned tube through the larger opening inthe peripheral wallof the housing, a plate detachably connected to saidhousing wall over said larger opening, the plate having a hole, and afuel supply pipe extending through said'hole and into the air supplytube and having its inner end turned downwardly and aligned with theapertures of said tubes.

l2. In liquid fuel burning apparatus, the combination of a burner bowl,an air supply tube leading substantially `horizontally into the bowl adistance above the bottom thereof and having an raperture in its underside through which it i liquid fuel 'f burningv e apparatus, the fcombination of a burnerbowl includinggaperiphwall of the housingA thefirstk mentioned tube, said tubes having registering apertures in v'vcommuhicates with the interior of the Yhema fuel supply 'pipe extendingin'to the air supply tube and arranged With its discharge nd in spacedrelation to the perimeter of said aperture so' that fuel discharged fromthe pipe will drop freely into' che `bowleiw'eloped by air entering thebowl through said aperture', and an insulating 'structure inludinga tubeentirely'enc'asing and radially spacedfrom the o'tin o'f the air`'supply tubewithin the bowl,--and end means separating thespace .betweensaid tubes from the interior offthe boWLth second xnn'ti'oned tubehaving Eny 'aperturein' `register Withithat of the .air supj ply tube.-

s. OHADWICK. EVANS W. CHEESEMAN. -ARTHUR R. MOORE.

i vEEFEEMBES CITED "'l'ijfl'low'ing'* references are f record in thef'12 UNITED STATES' PATENTS Number l5 Number Name Da't Petty gMay, 1910schaurnann Mar.' 31, 1925 Littl Dec. 22, 1925 Blake Dec. 27, 1927 4GrantDec. 8, r1931 Poore Deaf@ 1932 Qannon O t. 31, 1333 *Ramsey Oct. 1,5,1940 Keating June 2 4, V1941 Johnston Jan. 26, 1943 FOREIGN PATENTS

